This invention relates to fences of the type wherein a rail is supported parallel to the ground by inserting its end portions into holes in adjacent vertical posts. This invention can be used with concrete fence posts.
In the past it has been difficult to replace broken rails in this type of fence. Usually it was necessary to dig up one of the posts adjacent the broken rail in order to insert the replacement rail.
Another problem has been that wood fence posts tend to be adversely affected by moisture, weather, dry rot and insects. Among the solutions proposed have been the use of special wood varieties, chemical coating and alternate materials. Some species of wood, for example redwood, do ameliorate the durability problem but they do not eliminate it. Chemical coating is effective but the coating must be periodically reapplied to have continued effect and this usually requires removal of fence posts from the ground. Use of alternate materials such as metal and concrete is promising. However, metals are expensive and are subject to rust if they are not painted regularly. Concrete offers durability but so far such posts have not been extensively used because of the difficulty of attaching rails to these posts.
Prior art efforts to develop effective concrete fence posts include U.S. Pat. No. 859,239 to McFall, U.S. Pat. No. 3,451,657 to Roberts, U.S. Pat. No. 2,969,223 to Hansen, U.S. Pat. No. 984,711 to Stanley, and U.S. Pat. No. 2,578,165 to Bailey.
De Ridder in U.S. Pat. No. 3,276,750 discloses a fence in which rails are maintained by U-shaped mounting brackets. British Pat. No. 1,336,012 discloses a fence in which a wire is clamped to a post.